Pneumatic cushion with variable configuration &amp; constriction

ABSTRACT

A bladder formed inside or positioned on a seat accounts for variations in personal anatomy with changes in the configurations of multiple chambers in the bladder and may also allow for changes to the constriction between the chambers in the bladder. The bladder forms a cushioning device that is used for seating applications which involve movement and continuously changes softness between the chambers by using the movement of the rider. Rider movement results in the interchange of pressures through variable-sized orifices between variable-displacement chambers. The number and size of the chambers can be varied according to a desired seating configuration. The orifice size can be changed with a variable constriction mechanism. Different fastening configurations can change the number and shape of the chambers. The cushioning device can be used in retrofitting existing seats and can be produced in new seats.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication Ser. No. 61/790,844 filed on Mar. 15, 2013 which is herebyincorporated by reference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Not Applicable.

APPENDIX

Not Applicable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to pneumatic cushions and otherfluid-filled cushions, and more particularly to a pneumatic cushionhaving a variable configuration with multiple chambers and a variableconstriction of the flow between the chambers.

2. Related Art

Since the invention of the bicycle, the enjoyable activity of bicycleriding can become painful for both the buttocks and genitalia areas.Even before the invention of the bicycle, mankind looked for ways tocomfortably support themselves during riding activities; the inventionof the saddle is said to have occurred more than 3,000 years ago. The‘pain-in-the-butt’ problem has been tackled with many differenttechnologies over this lengthy period of time and has included leather,textile padding, springs, foam and gel cushions, and inflatablebladders. Problems with these technologies are widely varied (e.g., toocostly to manufacture; too complicated to execute manufacturing &marketing; advertised benefits not easily achieved or realized; pricepoints too expensive relative to competing products), but the one commonoccurrence is that they are mass-produced and not truly personalized tothe individual's comfort requirements. Attempts to solve the problemboil down to a maxim that personalized comfort cannot be mass produced.

Since personalized comfort continues to be sought and inflatablebladders conform to a user, there are many styles of inflatable cushionsfor various types of seats, particularly including bicycle seats.However, most inflatable cushions provide one or more bladders that arein a fixed configuration even though the location of riders' ischium andpubic bones can vary dramatically based on the rider's size, gender anda number of other factors. Additionally, even when these fixedconfiguration bladders have multiple chambers that try to support arange of sizes and allow for the communication of the airflow, they donot have any variation in the constriction between the chambers. Thislack of constriction may be important, particularly with bladders in afixed configuration because a variation in the constriction could helpprovide more personalized comfort based on the particular rider's size,gender or some other factor (i.e., no variable valves or othermechanisms between the chambers).

It is already known to use a multi-chamber bladder with an extensiontube that allows for airflow between the chambers and that also allowsthe chambers to be placed in various alternative configurations relativeto each other, such as described in U.S. Pat. No. 5,558,395. However,merely permitting chambers to have different distances between them isnot a solution to the problem of personalized comfort. There remains theissue of how much pressure should be in the chambers and what should bethe flow rate of fluid between the chambers. For example, consider thepossibility that there is sufficient pressure in two adjacent chambersin fluid communication with each other when a rider is in a steady stateposture, such as when the rider is coasting, but if there is not enoughconstriction in the passageway(s) between the chambers when the rider isin a dynamic riding mode, the side that needs to provide support (whichchanges from one side to the other with the pedaling action of therider) may merely collapse under the increased pressure of the rider andnot provide the required support.

Additionally, when it comes to the particular use of the multi-chamberbladder design for bicycle seats, such as in U.S. Pat. No. 5,558,395,the extension tube is described as being useful for locating a releasevalve at an adjustable distance from the cushion, and there is noconsideration given to the rate of the airflow between the cushions forthe dynamic mode of operation. Another multi-chamber bladder may havetwo entirely separate bladders, each with its own filling valve and withno air passage between the bladders such as in U.S. Pat. No. 6,305,743.Other multi-chamber bladder designs have upper and lower bladders, suchas in U.S. Pat. Nos. 608,857 and 611,377. The '377 Patent describes avalve mechanism between the bladders which can allow the downward flowof the air from the upper bladder to the lower bladder to pass morequickly than the return of the air from the lower bladder to the upperbladder. However, there is no allowance for the user to regulate thevalve mechanism or otherwise vary the rate of flow between the bladdersnor is there any ability for the user to change the configuration of thebladders.

It is clear that a multi-chamber bladder design by itself is notsatisfactory to provide the kind of personalized comfort that has beensought after with inflatable bladder technology. One issue with previousattempts to provide support that conforms to the rider, includinginflatable bladders as well as standard cushioning materials, is thefact that most designs are based on the same technology that is used forcushions that are optimized more for static conditions, such as cushionsused for chairs or beds. In static conditions, there is no repeatedpounding of the person's body against the cushioning material. More andmore bicycle frames that are designed for off-road use take the dynamicsof the road conditions into account in the design of the frame, andthese frame designs include structural supports that are seen in otherdynamic systems, like automotive vehicles and even aircraft, such asshock absorbers and designed frame deflection. However, unlikeautomotive vehicles and aircraft, where the pilots and drivers remain ina near steady-state seated position, a bike rider creates their owndynamics relative to the seat as they switch their power stroke from oneleg to the other. Given this understanding of the combined problem ofdynamics and personal comfort, it becomes more clear that the bladderdesigns that have typically been used for static seating arrangementscould not possibly be satisfactory for a problem in which the particularbone structure of rider impacts the dynamics of the power stroke and thecorresponding optimal support required from the seat.

Accordingly, there remains a need for an optimized cushion whichprovides the support that is required from the seat as a rider switchesthe power stroke from one leg to the other and which accounts forvariations in personal anatomy.

SUMMARY OF THE INVENTION

The cushioning device of the present invention solves the painfulproblem of seated activities with personalized comfort provided overextended periods of riding, including the dynamic activity of cyclingthe power stroke from one leg to the other. Accordingly, the inventivecushioning device allows personalized adjustment of softness/firmness ofa bladder formed inside or positioned on a seat and can also account forvariations in personal anatomy by changing the configurations ofmultiple chambers in the bladder as well as changing the constrictionbetween the chambers in the bladder.

The components of the cushioning device are uniquely integrated toenable a person to find their individual comfort level. The inventivecushioning device can also be used on other seats, and is particularlysuited for use on seats in which the user is engaged in an activity thatrequires a cyclical movement of the legs or adjustment in the seat suchas stationary biking (e.g., Spinning), rowing, horseback riding, andnumerous other seated activities.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more fully understood from thedetailed description and the accompanying drawings. The drawingsconstitute a part of this specification and include exemplaryembodiments of the invention, which may be embodied in various forms. Itis to be understood that in some instances, various aspects of theinvention may be shown exaggerated or enlarged to facilitate anunderstanding of the invention; therefore the drawings are notnecessarily to scale. In addition, in the embodiments depicted herein,like reference numerals in the various drawings refer to identical ornear identical structural elements.

FIGS. 1A, 1B, 1C and 1D are a top view, a side view, a back view and afront view of the invention, respectively.

FIGS. 2A and 2B are top views of alternative chamber configurationsaccording to the present invention.

FIGS. 3A and 3B are isometric views of alternative constrictionmechanisms according to the present invention.

FIG. 4 is an isometric view of an alternative chamber configuration andan alternative constriction mechanism according to the presentinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the preferred embodiment(s) is merelyexemplary in nature and is in no way intended to limit the invention,its application, or uses.

Most generally, as shown in FIGS. 1-4, the cushion 10 for a seat 100 hasone or more sealed bladders 12 having an interior portion 22, anexterior portion 24 and a volume 26. There are multiple chambers 14 inthe interior potion of the sealed bladder, a fluid communication path 16between the chambers, and a variable constriction 18 in the fluidcommunication path between the chambers. The sealed bladder preferablyincludes a filling valve 30 on the exterior portion so that a fluid suchas air can be pumped into the interior portion to vary the steady statepressure of the bladder. Although ambient air is the preferred fluidmedium for the present invention, it is possible that an inert gas or aliquid may also be used. The bladder can be positioned on an existingseat 100 as shown in FIGS. 1 and 2 or can be incorporated into anintegral seat design as shown in FIGS. 3 and 4. When the cushion 10 isadded to an existing seat 100, a seat cover 50 can be used over thesealed bladder 12 to provide a more finished appearance.

As particularly shown in FIGS. 2A and 2B, even for an identically shapedsealed bladder 12 that is similarly positioned on a seat 100, thechambers 14 a, 14 b, 14 c can be arranged with variable configurations20 with a different arrangement and number of chambers. As explainedbelow, different arrangements of the strap fasteners 32, 34 can createthe variations in the configuration of the chambers 14 and can also varythe constriction 18 in the fluid communication path 16 between thechambers 14. For example, the straps 34 can form the triangle-shapedconfiguration 20′ in FIG. 2A or the star-shaped configuration 20″ inFIG. 2B as variable configurations 20 of the same bladder in the sameposition on the same seat. The interior portion of the bladder in theseconfigurations has approximately the same volume, but the arrangement ofthe chambers varies. The triangle-shaped configuration divides thevolume approximately equally between each of the chambers 14 a, 14 b, 14c, but the star-shaped configuration divides the volume so that so thatat least one of the chambers 14 b has a larger volume than otherchambers 14 a′, 14 a″, 14 c′, 14 c″.

In each of these configurations, the variation in the tension 40 on thestraps 34 allows for the selectable constriction 18 which determines howthe airflow 28 is restricted between the chambers. For example, a looserfit of the straps 34 with lesser tension 40 on the straps 34 would allowair to more freely travel between the chambers while a tighter fit wouldbe more restrictive of the airflow between the chambers respectivelyproducing a higher flow rate 28′ and a lower flow rate 28″. The straps34 actually function with the sealed bladder 12 to form a type of valve46, namely a pinch valve 48.

The straps 34 are held in place with anchors 36 and fasteners 32. Forexample, an upper anchor 36 a and a lower anchor 36 b may be used asshown in FIGS. 1 and 2. The straps 34 are radially spaced from eachother around the circumference of the bladder 12 and longitudinallyextend over the bladders' exterior portion between the anchors 36 toform the chambers 14 in the interior portion as well as the fluidcommunication paths 16. The fluid communication paths are restricted bya pinch valve 48 that is varied according to the tension 40 of thestraps 34 that are pulled over the bladder; accordingly, the strapsdefine the fluid communication paths as well as the variableconstriction and the configuration of the chambers. As explained abovewith respect to FIGS. 2A and 2B, the straps have alternate fixationpaths between the anchors that produce the chambers' variableconfigurations. Accordingly, the straps not only allow for a variableconfiguration of the bladder/chamber, but the straps also provide therider with the ability to vary the constriction of the passagewaysbetween the chambers.

It will be appreciated that configurations other than thetriangle-shaped configuration and the star-shaped configuration can becreated and bladders with other shapes can be uses. Even with thering-shaped bladder shown in FIGS. 1 and 2, a figure-8 configurationcould be produced, and this configuration may be secured to the seat ina side-to-side arrangement or a front-to-rear arrangement. The chamberscan also be in fluid communication with each other through a tube 44.Such chambers 14 may be situated on a seat as generally described aboveor may be integrally incorporated into the design of a seat as shown inFIGS. 3 and 4.

As shown in FIGS. 3A and 3B, it is possible to incorporate the bladderchambers 14 into a seat 100 with a tube 44 that is external to the seatwhich also has an external valve connected to the external portion ofthe tube. FIG. 4 shows an example where tubes 44 may remain inside theseat with the chambers 14, but a pinch valve strap 46 extends out of thebottom of the seat or out from the periphery of the seat so that a ridercan adjust the tension on the strap and control the flow rate throughthe tubes. In FIG. 3A, a pinch valve 48 is shown connected to thepliable section 52 of the tube 44 that is in external portion. It willalso be appreciated that some tube designs may be more rigid and couldhave any type of variable flow rate valve that the rider uses to set thevariable constriction, such as generally shown in FIG. 3B. Thisadjustment of the valve can be done by a knob or a standard bicycle toolthat adjusts the valve, depending on the type of valve which could be aball valve, a butterfly valve, a gate valve, a needle valve, the pinchvalve and any other valve that would permit a variable selection of flowrates through the valve.

As particularly shown in FIG. 4, the straps 46 extend over a securedsection of the tube 44. In such a case, the tube is preferably formedfrom a pliable material, and the strap has a fastener that varies thetension in the strap. The tension variation varies a deformation in thesecured section of the pliable tube and provides the variableconstriction.

Other known features of pneumatic cushions could also be incorporatedinto one or more of the designs described above. For example, thecushion could use a self-inflating bladder that has a resilient materialwhich defines the volume for air at ambient conditions when the externalvalve is open or that uses the body weight of the rider to maintain thepressure and could also incorporate a variable-pressure check valve thatwould prevent the bladder from becoming over-inflated and that the ridercould use to set the desired pressure within the system. Of course, arider could still have variations in the constriction between thechambers, but the overall pressure could be set by a check-valve. Thebladder may be inflated by a separate pump or by a bulb pump 54 that isintegrated into the cushion system as shown in FIG. 4.

Several features and benefits of the inventive cushioning device arelisted in the tables below.

Features Adjustable (male/female; height/weight; personalize desiredcomfort (i.e., softness) level) Adaptable (all types (smooth/rough)terrain) Anatomically Friendly (minimize the dreaded genitilia/perineumeffects such as Pudendal Nerve Entrapment, Impotence, Yeast Infections,Ischial bursitis (i.e., “pain-in-the-butt”), etc.). Neither Male norFemale is immune from some of these aliments/conditions.

Benefits Perceived comfort Adjustable to the specific individualAdaptable to different terrains and riding conditionsInterchangeable/Adapatable to different bicycles Anatomically FriendlyLow cost to manufacture Easily installed to an existing seat or seatbase Sans electronic or mechanical devices Easy to adjust firmnessSeparate Seat/Cushioning Cover designed to fit the variability of thelevel of firmness. Increasing or decreasing the number of chambers iseasily done by either increasing or decreasing the number of fasteningstraps and/or reconfiguring the fastening straps as the fastening strapssegment/divided the bladder. The changing of pressures between and amongthe chambers within the bladders thru the natural movement of theindividual sitting on the cushion. Pliability of the bladder allows forcontinuous comfort regardless of the ambient temperature. All cushioningdevice components moisture resistant Single Chamber cushioning devicesdo not allow for changing of pressure Independent Multi-chamberedcushioning devices do not allow for the cushioning medium to movebetween and among the chambers. Cushioning medium can be air, inert gas,or liquid such as water.. Bladder construction of Halogenatedisobutylene-co-alkylstyrene polymer, preferably halogenatedisobutylene-co-methylstyrene polymer, even more preferably brominatedisobutylene-co-paramethylstyrene polymer (BIMS) and blends with a secondrubber is preferred Bladder inflation/deflation valve either Schrader orPresta. Fastening straps can be constructed of either flexible(elastomeric) (i.e., Bungee Cord) or rigid materials. Both ends of eachfastening strap has a hook, clip or other connector/fastener. Forexample, Bungee cords typically comprise a stretchable cord and a hookfastened at either end.

The components of the cushion 10 as described above with reference toFIGS. 1 and 2 are generally described below along with a method ofassembling and operating the cushioning device. The bladder 12 isflexible with both reflection and deflection characteristics. Thefilling valve 30 is preferably self-closing, such as a biased closedSchrader valve or Presta valve that are commonly used for bicycle tiretubes. The fastening straps 34 can be elastic or inelastic and are sizedaccording to their length and width and preferably include clips, hooksor other fasteners or connectors 42 on each end. The anchor rings 36 arepreferably made of steel with an anti-rusting finish. The cover ispreferably made of moisture resistant, stretchable material. There maybe an optional air hose extension 56 for larger seat profiles.

An existing seat maybe used as the base for the cushion device accordingto the present invention. Remove the seat from bicycle with the seatstem 110 attached to the seat 100. Place the seat stem 110 through thelower anchoring ring 36 b. Remount the seat and seat stem on thebicycle. Attach the firmness extension hose 56 to the filling valve 30on the bladder 12. Center the deflated bladder 12 on top of the seatwith valve facing down toward the top of the seat. The firmnessextension hose should be between the deflated bladder and the top of theseat. Inflate the deflated bladder with a small amount of air throughthe firmness extension hose. Take one fastening strap 34 and thread itthrough the upper anchoring ring 36 a which will be centered on the top38 of the partially inflated bladder. Take another fastening strap 34and also thread it through the upper anchoring ring 36 a. Fasten thestraps to the lower anchoring ring 36 b using the hooks or otherconnectors 42 at the end of the straps. The anchoring straps can havefixation paths at 10 o′clock/7 o′clock for one strap and 2 o′clock/5o′clock for the other strap although this can be varied depending on thepreference of the rider and the type of seat on which the bladder isbeing fitted. When all of the straps are fastened to the respectivelower anchoring ring, additional air pressure can be added to thebladder.

It may be noted that riders who have used other types of inflatablecushions may have a tendency to make the seat rock hard with the airpressure. This has two (2) inherent problems: (1) the potential toover-inflate the bladder which could result in the bladder bursting and(2) for personal comfort, rock hard firmness will not yield a verycomfortable ride. Accordingly, it is preferred to gradually inflate thebladder to find the right personalized softness/firmness pressure forthe type of riding a person wants to do. If the seat is too hard, aircan be released through the inflation valve 30 just would be done forthe tires on the bike.

When the seat is situated back on the bike, the enclosed cover 50 mayalso be placed on the seat. It is preferred that the firmness extensionhose 56 should remain accessible on the bottom side of the seat.

Finding the preferred softness/firmness pressure is a ‘trial & error’process. The personal comfort/mass-production maxim remains in place sovariations based on particular riders can be expected. In addition tothe seat cushion, riding comfort is also based on the height of the seatand the position of the handlebars, and all of these variations arebased on the personal physical attributes of the rider. A key thatcharacterizes the width of a person's ischium is provided in the tablebelow.

Key Measurement For Ischium (Sit Bones) “Narrow” <100 mm (or 4 inches)“Medium” >100 mm & <130 mm (or between 4 & 5⅛ inches) “Wide” >130 mm (or5⅛ inches)

Seat sizes can be estimated through measurement. However, personalizedcomfort sizes are personal, regardless of what the measurements mightotherwise suggest.

Once the bladder 12 has been secured to the seat 100 with the fasteningstraps 34 and the two (2) anchor rings 36, inflating the bladder withthe cushioning medium begins with the injection of the cushioningmedium. The results of the process of inflating the bladder aresummarized in the steps provided below.

As pressure in the bladder is increased, the bladder begins to expand aswould a balloon would if it were being filled with water or air.Resistance of portions of the bladder begin to occur where the fasteningstraps cross the top of the bladder. As the bladder fills, compressionof the walls of the bladder begin to contort the shape of the fasteningstraps. Since the bladder walls are more pliable than the rigidfastening straps, orifices begin to form. The formation of the chambersand orifices is due to the increasing pressure in the bladder as it isinflated, the increased tightening of the fastening straps or acombination of both. With the seat cover secured, the weight of theperson sitting on the seat (i.e., bladder) results in additional staticdownward pressure on the bladder. Sitting “still” on the seat permitsthe pressures within each chamber to equalize (steady-state pressure).

Pressures within the chambers begin to change with shifting of theweight of the person sitting on the seat. Movement such as the cyclicalpedaling motion of a bicycle causes the weight of the person to shift invarious planes relative to the plane of the seat and bladder. Shiftingof weight forces the cushion medium to exit one chamber and enteranother chamber. The movement of the cushioning medium results in thechambers becoming firmer (i.e., harder) or becoming less firm (i.e.,softer). As long as movement of the person continues, there will be aconstant changing of pressures between or among the chambers.

Rider movement results in the interchange of pressures throughvariable-sized orifices between variable-displacement chambers. Thenumber and size of the chambers can be varied according to a desiredseating configuration. The orifice size and shape can be changed usingthe variable constriction and may also change according to the weight,posture, and movement of the person sitting on the device. Changing thenumber of chambers is dependent upon the desired fastening configurationwhich is also dependent on the end-use application. This cushioningdevice will work for both retrofitting existing seats and for new seats.

As described above, the bladder can be separate from both the cover andthe seat base or it can be integral with the seat. The anchoringmechanism of bladder to the seat base can be fastening straps with clipson their ends or any other mechanism that holds multiple chambers on orin the seat and tubes between the chambers. When using fastening straps,free-standing anchoring rings that float can accommodate differentinflation pressures and the different configurations produced by variousarrangements of the fastening straps. When the bladder is separate fromthe seat, the number of bladder chambers can be changed as desired andcan be easily interchangeable between bikes.

It will be appreciated that the combination of multiple chambers whichcan be changed and varying of pressures within the chambers enables ananatomically-friendly configuration to accommodate both genders. Theembodiments were chosen and described to best explain the principles ofthe invention and its practical application to persons who are skilledin the art. As various modifications could be made to the exemplaryembodiments, as described above with reference to the correspondingillustrations, without departing from the scope of the invention, it isintended that all matter contained in the foregoing description andshown in the accompanying drawings shall be interpreted as illustrativerather than limiting. Thus, the breadth and scope of the presentinvention should not be limited by any of the above-described exemplaryembodiments, but should be defined only in accordance with the followingclaims appended hereto and their equivalents.

What is claimed is:
 1. A cushion for a seat, comprising: a sealedbladder having an interior portion and an exterior portion; a pluralityof chambers in said interior potion of said sealed bladder; a fluidcommunication path between said plurality of chambers; and a variableconstriction in said fluid communication path between said plurality ofchambers, wherein said variable constriction has a first selectableconstriction and a second selectable constriction, wherein said firstselectable constriction and said second selectable constrictionrespectively correspond with a first flow rate and a second flow ratethrough said fluid communication path and wherein said second flow rateis greater than said first flow rate.
 2. The cushion of claim 1, whereinsaid sealed bladder further comprises a filling valve on said exteriorportion through which a fluid is pumped into said interior portion. 3.The cushion of claim 1, further comprising a set of fasteners holdingsaid sealed bladder on the seat and providing a variable configurationof said plurality of said chambers on the seat, wherein said variableconfiguration has a plurality of selectable configurations.
 4. Thecushion of claim 3, wherein said interior portion of said sealed bladderhas a volume, wherein a first selectable configuration divides saidvolume approximately equally between each of said chambers and wherein asecond selectable configuration divides said volume with at least one ofsaid chambers having a larger volume than another of said chambers. 5.The cushion of claim 1, further comprising a seat stem, a plurality ofstraps, an upper anchor, a lower anchor and a plurality of fluidcommunication paths, wherein said sealed bladder is positioned on theseat, wherein said upper anchor is positioned at a top of said exteriorportion of said sealed bladder, wherein said lower anchor is positionedaround said seat stem, wherein said straps are radially spaced aroundsaid exterior of said sealed bladder and longitudinally extend over saidexterior portion of said sealed bladder and the seat between said loweranchor and said upper anchor.
 6. The cushion of claim 5, wherein atension in said straps around said exterior of said sealed bladder formsaid fluid communication path between said plurality of chambers in saidinterior portion and a selectable amount of said tension produces saidvariable constriction in each of said fluid communication paths, whereina selective fastening of said straps between said lower anchor and saidupper anchor produces said selectable amount of said tension.
 7. Thecushion of claim 6, wherein said straps are further comprised of a setof connectors, wherein said connectors cooperate with said respectivestraps to produce said selectable amount of tension.
 8. The cushion ofclaim 5, wherein said straps have alternative sets of radial fixationpaths between said lower anchor and said upper anchor, and wherein saidalternate fixation paths produce a variable configuration of saidchambers.
 9. The cushion of claim 1, wherein said fluid communicationpath is comprised of a tube extending between said plurality of chambersand wherein said variable constriction is a valve connected to saidtube.
 10. The cushion of claim 9, wherein said tube has a pliablesection and wherein said valve is comprised of a pinch valve, whereinsaid pinch valve comprises a variable restrictor extending around saidpliable section of said tube.
 11. The cushion of claim 1, furthercomprising a seat cover over said sealed bladder.
 12. A cushion for aseat, comprising: a sealed bladder positioned on the seat, wherein saidsealed bladder has a volume in an interior portion and a filling valvebetween an exterior portion and said interior portion; a plurality ofchambers in said interior potion of said sealed bladder; a fluidcommunication path between said plurality of chambers; and a set offasteners holding said sealed bladder on the seat and providing avariable configuration of said plurality of said chambers on the seat,wherein said variable configuration has a plurality of selectableconfigurations.
 13. The cushion of claim 12, wherein a first selectableconfiguration divides said volume approximately equally between each ofsaid chambers and wherein a second selectable configuration divides saidvolume with at least one of said chambers having a larger volume thananother of said chambers.
 14. The cushion of claim 12, furthercomprising a variable constriction in said fluid communication pathbetween said plurality of chambers, wherein said variable constrictionhas a first selectable constriction and a second selectableconstriction, wherein said first selectable constriction and said secondselectable constriction respectively correspond with a first flow rateand a second flow rate through said fluid communication path and whereinsaid second flow rate is greater than said first flow rate.
 15. Thecushion of claim 14, further comprising a seat stem and wherein said setof fasteners are comprised of a plurality of straps, an upper anchor anda lower anchor, wherein said upper anchor is positioned at a top of saidexterior portion of said sealed bladder, wherein said lower anchor ispositioned around said seat stem, and wherein said straps are radiallyspaced around said exterior of said sealed bladder and longitudinallyextend over said exterior portion of said sealed bladder and the seatand are connected to said lower anchor and said upper anchor.
 16. Thecushion of claim 15, wherein said straps have alternative sets of radialfixation paths between said lower anchor and said upper anchor, whereinsaid alternate fixation paths produce said variable configuration ofsaid chambers, and wherein said straps function as a pinch valve betweensaid plurality of chambers and produce said variable constriction insaid fluid communication path.
 17. The cushion of claim 14, wherein saidfluid communication path is comprised of a tube extending between saidplurality of chambers and wherein said variable constriction is a valveconnected to said tube.
 18. A cushion for a seat, comprising: a sealedbladder positioned on the seat, wherein said sealed bladder has a volumein an interior portion and a filling valve between an exterior portionand said interior portion; a plurality of chambers in said interiorpotion of said sealed bladder; a plurality of fluid communication pathsbetween said plurality of chambers; a set of fasteners holding saidsealed bladder on the seat and providing a variable configuration ofsaid plurality of said chambers on the seat, wherein said variableconfiguration has a plurality of selectable configurations; and avariable constriction in each of said fluid communication paths betweensaid plurality of chambers, wherein said variable constriction has afirst selectable constriction and a second selectable constriction,wherein said first selectable constriction and said second selectableconstriction respectively correspond with a first flow rate and a secondflow rate through said fluid communication path and wherein said secondflow rate is greater than said first flow rate.
 19. The cushion of claim18, further comprising a seat stem and wherein said set of fasteners arecomprised of a plurality of straps, an upper anchor and a lower anchor,wherein said upper anchor is positioned at a top of said exteriorportion of said sealed bladder, wherein said lower anchor is positionedaround said seat stem, and wherein said straps are radially spacedaround said exterior of said sealed bladder and longitudinally extendover said exterior portion of said sealed bladder and the seat and areconnected to said lower anchor and said upper anchor.
 20. The cushion ofclaim 19, wherein said straps have alternative sets of radial fixationpaths between said lower anchor and said upper anchor, wherein saidalternate fixation paths produce said variable configuration of saidchambers, and wherein said straps function as a pinch valve between saidplurality of chambers and produce said variable constriction in saidfluid communication paths.